<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
	<title> new document </title>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
	<!--   引入jQuery -->
	<script src="../../scripts/jquery.js" type="text/javascript"></script>
	<script type="text/javascript">
		$(function(){
		  //注意区分类似这样的选择器
		  //虽然一个空格，却截然不同的效果.
		   var $t_a = $('.test :hidden');
		   var $t_b = $('.test:hidden');
		   var len_a = $t_a.length;
		   var len_b = $t_b.length;
		   $("<p>$('.test :hidden')的长度为"+len_a+"</p>").appendTo("body");
		   $("<p>$('.test:hidden')的长度为"+len_b+"</p>").appendTo("body");
		})
	</script>
</head>
<body>
	<div class="test">
	   <div style="display:none;">aa</div>
	   <div style="display:none;">bb</div>
	   <div style="display:none;">cc</div>
	   <div class="test" style="display:none;">dd</div>
	</div>
	<div class="test" style="display:none;">ee</div>
	<div class="test" style="display:none;">ff</div>
</body>
</html>
